Some methods are known for producing flavoring agents derived from milk or milk products: for example, a method in which fresh cream or milk is treated with an enzyme derived from animal pharynx (U.S. Pat. Nos. 3,469,993, 3,650,768); a method in which milk or cream is treated with lipase derived from a microorganism (Japanese Published Examined Patent Application No. 3187/70); a method in which butter is hydrolyzed and then treated with lipase derived from a microorganism in the presence of an alcohol [Journal of the Japanese Society for Food Science and Technology, Vol. 30, p. 572 (1983)]; a method in which vegetable fats and oils are hydrolyzed and then treated with lipase derived from a microorganism in the presence of an alcohol (Japanese Published Examined Patent Application No. 50554/81); and a method in which butter oil is treated with esterase derived from an animal in the absence of an alcohol and then treated with lipase (Japanese Published Unexamined Patent Application No. 66856/84). The flavoring agents derived from milk or milk products which are obtained by the above methods have a butter flavor or a cheese flavor, but do not have a rich fruity flavor.
It is known that large amounts of higher fatty acid ethyl esters are formed by treating, in the presence of ethanol, butter fat with lipase derived from a microorganism [Journal of the Japanese Society for Food Science and Technology, Vol. 30, p. 572 (1983)]. However, flavoring agents containing quantities of higher fatty acid alkyl esters have waxy smell and taste.
In another known method, an enzyme derived from animal liver or kidney having a high ester-synthesizing activity is brought into contact with foods and beverages to impart a fruit flavor thereto (WO 93/09681). However, the treatment of milk or milk products with only escerase derived from animal liver or kidney would produce rather grassy smell than a fruit flavor.